Inputs¶
List of inputs of EPW v5.8¶
&inputepw¶
A adapt_ethrdg_plrn, a2f, amass, asr_typ, assume_metal
B band_plot, bands_skipped, bfieldx, bfieldy, bfieldz, bnd_cum, broyden_beta, broyden_ndim
C cal_psir_plrn, carrier, conv_thr_iaxis, conv_thr_plrn, conv_thr_racon, conv_thr_raxis, cumulant
D degaussq, degaussw, delta_approx, delta_qsmear, delta_smear, dvscf_dir, do_CHBB
E efermi_read, eig_read, elecselfen, eliashberg, elph, ep_coupling, epbwrite, epbread, epexst, ephwrite, epmatkqread, eps_acustic, epsiHEG, epwread, epwwrite, etf_mem, ethrdg_plrn
F fermi_diff, fermi_energy, fermi_plot, fila2f, fildvscf, filkf, filqf, filukk, filukq, fixsym, fsthick
G gap_edge, gb_scattering, gb_only, gb_size
I imag_read, init_ethrdg_plrn, init_k0_plrn, init_ntau_plrn, init_plrn, init_sigma_plrn, interp_Ank_plrn, interp_Bqu_plrn, int_mob, io_lvl_plrn, iterative_bte, iverbosity, ii_g, ii_scattering, ii_only, ii_lscreen, ii_partion, ii_charge, ii_n, ii_eda
L lacon, laniso, lifc, limag, lindabs, liso, longrange, lpade, lphase, lpolar, lreal, lscreen, lunif, loptabs, len_mesh
M max_memlt, meff, mob_maxiter, mp_mesh_k, mp_mesh_q, muc, meshnum
N nbndsub, ncarrier, nc, nel, nest_fn, nethrdg_plrn, ngaussw, niter_plrn, nk1, nk2, nk3, nkf1, nkf2, nqf3, nq1, nq2, nq3, nqf1, nqf2, nqf3, npade, nqsmear, nqstep, n_r, nsiter, nsmear, nstemp, nswi, nswc, nswfc, nw, nw_specfun, nq_init
O omegamax, omegamin, omegastep
P phonselfen, plselfen, plrn, prefix, prtgkk, pwc
R rand_nq, rand_nk, rand_q, rand_k, restart, restart_filq, restart_plrn, restart_step
S scell_mat, scell_mat_plrn, scr_typ, scatread, scattering, scattering_serta, scattering_0rta, scissor, selecqread, smear_rpa, specfun_el, specfun_ph, specfun_pl, system_2d, shortrange, step_wf_grid_plrn, start_mesh
T temps, tc_linear, tc_linear_solver, type_plrn
V vme
W wannierize, wepexst, wmax, wmax_specfun, wmin, wmin_specfun, wscut, wsfc
/
— If wannierize = .true. the following input variable apply
auto_projections, dis_froz_min, dis_froz_max, iprint, num_iter, proj, reduce_unk, scdm_entanglement, scdm_mu, scdm_proj, scdm_sigma, wannier_plot, wannier_plot_list, wannier_plot_radius, wannier_plot_scale, wannier_plot_supercell, wdata
— If a file named quadrupole.fmt is present in the running directory, the code will use quadrupoles to perform the interpolation of the electronphonon matrix elements and dynamical matrices. The structure of the file is as follow:
atom dir Qxx Qyy Qzz Qyz Qxz Qxy
1 1 XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
1 2 XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
1 3 XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
2 1 XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
2 2 XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
2 3 XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
...
where XXXXXXXX have to be replaced by the value of the quadrupoles which can be obtained, for example, using the ABINIT software
a2f
¶
Type 
LOGICAL

Default 
.false.

Description 
Calculate Eliashberg spectral function, \(\alpha^2F(\omega)\), transport Eliashberg spectral function \(\alpha^2 F_{\rm tr}(\omega)\), and phonon density of states \(F(\omega)\). Only allowed in the case of phonselfen = .true.

amass(:)
¶
Variable 
amass(i), i=1,ntyp

Type 
REAL

Default 
0.0

Description 
Atomic mass [amu] of each atomic type. If not specified, masses are read from data file.

asr_typ
¶
Type 
CHARACTER

Default 
‘simple’

Description 
Kind of acoustic sum rule that can be imposed in real space. Possible ASR are ‘simple’, ‘crystal’, ‘onedim’ and ‘zerodim’.

assume_metal
¶
Type 
LOGICAL

Default 
.false.

Description 
Assume we have a metal. This flag should only be activated in the context of transport (conductivity or resistivity) calculations. In that case use a FermiDirac distribution.

band_plot
¶
Type 
LOGICAL

Default 
.false.

Description 
bands_skipped
¶
Type 
CHARACTER

Default 
'' 
Description 
List of bands to exclude from the wannierization, where the number of excluded bands should be smaller or equal to nbndskip. For example,
bands_skipped = 'exclude_bands = 1:5' means the first 5 bands are excluded from the wannierization. 
bfieldx, bfieldy, bfieldz
¶
Type 
REAL

Default 
0.0

Description 
The magnetic field in the x, y and z Cartesian directions in [Tesla].

bnd_cum
¶
Type 
INTEGER

Default 
1

Description 
Band index for which the cumulant calculation is done. For more than one band, you need to perform multiple calculation and add the results together.

broyden_beta
¶
Type 
REAL

Default 
0.7

Description 
Mixing factor for Broyden mixing scheme.

broyden_ndim
¶
Type 
INTEGER

Default 
8

Description 
Number of iterations used in the Broyden mixing scheme.

carrier
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. it computes the intrinsic electron or hole mobility such that the carrier concentration is given by ncarrier.

conv_thr_iaxis
¶
Type 
REAL

Default 
1.d05

Description 
Convergence threshold for iterative solution of imaginaryaxis Eliashberg equations.

conv_thr_racon
¶
Type 
REAL

Default 
5.d05

Description 
Convergence threshold for iterative solution of the analytic continuation of Eliashberg equations from imaginary to realaxis.

conv_thr_raxis
¶
Type 
REAL

Default 
5.d04

Description 
Convergence threshold for iterative solution of realaxis Eliashberg equations.

cumulant
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. calculates the electron spectral function using the cumulant expansion method. Can be used as independent postprocessing by setting ep_coupling =.false.

degaussq
¶
Type 
REAL

Default 
0.05

Description 
Smearing for sum over q in the eph coupling in [meV]

degaussw
¶
Type 
REAL

Default 
0.025

Description 
Smearing in the energyconserving delta functions in [eV]

delta_approx
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. the double delta approximation is used to compute the phonon selfenergy.

delta_qsmear
¶
Type 
REAL

Default 
0.05

Description 
Change in the energy for each additional smearing in the a2f in [meV].

delta_smear
¶
Type 
REAL

Default 
0.01

Description 
Change in the energy for each additional smearing in the phonon selfenergy in [eV]

dvscf_dir
¶
Type 
CHARACTER

Default 
‘./’

Description 
Directory where ‘prefix.[dvscfdyn]_q??’ files are located.

do_CHBB
¶
Type 
LOGICAL

Default 
.false.

Description 
Use CHBB theory for optical absorption calculation.

efermi_read
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. the Fermi energy is read from the input file.

eig_read
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. then read a set of eigenvalues from ksdata.fmt. Can be used to read GW (or other) eigenenergies. The code expect a file called “prefix.eig” to be read. One need to provide the same number of bands as in the nscf calculations and all kpoints.

elecselfen
¶
Type 
LOGICAL

Default 
.false.

Description 
Calculate the electron selfenergy from the elph interaction

eliashberg
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. solve the Eliashberg equations and/or calculate the Eliashberg spectral function.
1) if laniso =.true., the anisotropic Eliashberg equations are solved. This requires that .ephmat, .freq, .egnv, .ikmap files are read from the disk. The files are written when ephwrite =.true. in the input file (see ephwrite variable).
2) if liso =.true., the isotropic Eliashberg equations are solved. This requires that either (a) .ephmat, .freq, .egnv, .ikmap files (see ephwrite variable) or (b) isotropic Eliashberg spectral function file (see fila2f variable) are read from the disk.
3) if .not. laniso and .not. liso , the Eliashberg spectral function is calculated. This requires that .ephmat, .freq, .egnv, .ikmap files are read from the disk. The files are written when ephwrite =.true. in the input file (see ephwrite variable).
Note: To reuse .ephmat, .freq, .egnv, .ikmap files obtained in a previous run, one needs to set ep_coupling =.false., elph =.false., and ephwrite =.false. in the input file.

ep_coupling
¶
Type 
LOGICAL

Default 
.true.

Description 
If .true. run eph coupling calculation.

epbwrite, epbread
¶
Type 
LOGICAL

Default 
.false.

Description 
If epbwrite = .true., the electronphonon matrix elements in the coarse Bloch representation and relevant data (dyn matrices) are written to disk. If epbread = .true. the above quantities are read from the ‘prefix.epb’ files. Pool dependent files.

epexst
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. then prefix.epmatwp files are already on disk (don’t recalculate). This is a debugging parameter.

ephwrite
¶
Type 
LOGICAL

Default 
.false.

Description 
Writes 4 files (in prefix.ephmat directory) that are required when solving the Eliashberg equations. ‘ephmatXX’ (XX: pool dependent files) files with eph matrix elements within the Fermi window (fsthick) on fine k and q meshes on the disk, ‘freq’ file contains the phonon frequencies, ‘egnv’ file contains the eigenvalues within the Fermi window, and ‘ikmap’ file contains the index of the kpoint on the irreducible grid within the Fermi window. These files are required to solve the Eliashberg equations when eliashberg = .true.. The files can be reused for subsequent evaluations of the Eliashberg equations at different temperatures. ephwrite doesn’t work with random k or qmeshes and requires nkf1,nkf2,nkf3 to be multiple of nqf1,nqf2,nqf3.

epmatkqread
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. restart an IBTE calculation from scattering written to files.

eps_acustic
¶
Type 
REAL

Default 
5.d0

Description 
The lower boundary for the phonon frequency in elph and a2f calculations in [cm1].

epsiHEG
¶
Type 
REAL

Default 
0.25d0

Description 
Dielectric constant at zero doping for electronplasmon.

epwread
¶
Type 
LOGICAL

Default 
.false.

Description 
If epwread = .true., the electronphonon matrix elements in the coarse Wannier representation are read from the ‘epwdata.fmt’ and ‘XX.epmatwpX’ files. Each pool reads the same file. It is used for a restart calculation and requires kmaps = .true. A prior calculation with epwwrite = .true is also required.

epwwrite
¶
Type 
LOGICAL

Default 
.true.

Description 
If epwwrite = .true., the electronphonon matrix elements in the coarse Wannier representation and relevant data (dyn matrices) are written to disk. Each pool reads the same file.

etf_mem
¶
Type 
INTEGER

Default 
1

Description 
If etf_mem = 1, then all the fine Blochspace elph matrix elements are stored in memory (faster). When etf_mem = 1, more IO (slower) but less memory is required. When etf_mem = 2, an additional loop is done on mode for the fine grid interpolation part. This reduces the memory further by a factor “nmodes”. The etf_mem = 3 is like etf_mem = 1 but the fine kpoint grid is generated with points within the fsthick window using kpoint symmetry (mp_mesh_k = .true. is needed) and the fine qgrid is generated on the fly. The option etf_mem = 3 is used for transport calculations with ultra dense fine momentum grids.

fermi_diff
¶
Type 
REAL

Default 
1.d0

Description 
Difference between Fermi energy and band edge (in eV). Only relevant when lscreen = .true.

fermi_energy
¶
Type 
REAL

Default 
0.d0

Description 
Value of the Fermi energy read from the input file in [eV].

fermi_plot
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true., write Fermi surface files (in .cube format which can be plotted with VESTA) on nkf1, nkf2, nqf3.

fila2f
¶
Type 
CHARACTER

Default 
'' 
Description 
Input file with isotropic Eliashberg spectral function. The file contains the Eliashberg spectral function as a function of frequency in [meV]. This file can only be used to calculate the isotropic Eliashberg equations. In this case
*.ephmat , *.freq , *.egnv , and *.ikmap files are not required. 
fildvscf
¶
Type 
CHARACTER

Default 
'' 
Description 
Output file containing deltavscf (not used in calculation)

filkf
¶
Type 
CHARACTER

Default 
‘./’

Description 
File which contains the fine kmesh or the kpath of electronic states to be calculated for elinterp. Crystal coordinates.

filqf
¶
Type 
CHARACTER

Default 
‘./’

Description 
File which contains the fine qmesh or the qpath of phonon states to be calculated for phinterp. Crystal coordinates.

filukk
¶
Type 
CHARACTER

Default 
‘prefix.ukk’

Description 
The name of the file containing the rotation matrix U(k) which describes the MLWFs.

filukq
¶
Type 
CHARACTER

Default 
‘prefix.ukq’

Description 
The name of the file containing the rotation matrix U(k+q) which describes the MLWFs.

fixsym
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. try to fix the symmetryrelated issues.

fsthick
¶
Type 
REAL

Default 
1.d10

Description 
Width of the Fermi surface window to take into account states in the selfenergy delta functions in [eV]. Narrowing this value reduces the number of bands included in the selfenergy calculations.

gap_edge
¶
Type 
REAL

Default 
0.d0

Description 
Initial guess for the superconducting gap edge if gap_edge .gt. 0.d0 in [eV]. Otherwise the initial guess for the gap is estimated based on the critical temperature found from the AllenDynes formula and BCS ratio (2*gap/T_c=3.52)

gb_scattering
¶
Type 
LOGICAL

Default 
.false.

Description 
If .TRUE. it calculates grain boundary scattering rate \(\tau_{n\bf{k}} =  \bf{v}_{n\bf{k}}  / L\),
where \(\bf{v}_{n\bf{k}}\) is band group velocity and \(L\) is grain size

gb_only
¶
Type 
LOGICAL

Default 
.false.

Description 
If .TRUE. it calculates only the grainboundarylimitted mobility

imag_read
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. read from file the superdconducting gap and renormalization function on the imaginaryaxis at a temperature XX. The required file is ‘prefix.imag_aniso_XX’. The temperature should be specified as temps(1) =XX in the input file. This flag works if limag =.true. and laniso =.true., and can be used to:
(1) solve the Eliashberg equations on the realaxis with lpade =.true. or lacon =.true. starting from the imaginaryaxis solutions at temperature XX;
(2) solve the Eliashberg equations on the imaginaryaxis at temperatures grater than XX using as a starting point the gap estimated at temperature XX.
(3) write to file the superconducting gap on the Fermi surface in cube format at temperature XX. The output file is ‘prefix.imag_aniso_gap_XX_YY.cube’, where YY is the band number within the chosen energy window during the EPW calculation. The file is written if iverbosity =2.

int_mob
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. and carrier = .false. it compute the intrinsic mobility such that the electron carrier concentration and hole concentration are the same (only one Fermi level) and give both electron and hole mobility in the same run. If the gap is too big, the number of carrier will be so small that the code will be unstable. If .true. and carrier = .true. it will compute the intrinsic electron and hole mobility with two Fermi level such that the electron and hole carrier concentration is ncarrier.

iterative_bte
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. it compute the iterative Boltzmann Transport Equation (IBTE) intrinsic mobility such that the electron carrier concentration and hole concentration are the same (only one Fermi level) and give both electron and hole mobility in the same run. If the gap is too big, the number of carrier will be so small that the code will be unstable. If .true. and carrier = .true. it will compute the intrinsic electron and hole mobility with two Fermi level such that the electron and hole carrier concentration is ncarrier. Also see mob_maxiter.
Note that the IBTE can only be solved on a homogeneous grid. You can use kpoint symmetry to reduce the computational time with mp_mesh_k.

iverbosity
¶
Type 
INTEGER

Default 
0

Description 
0 = short output
1 = verbose output.
2 = verbose output for the superconducting part only.
3 = verbose output for the electronphonon part only [mode resolved linewidths etc..].

ii_g
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. it calculates the ionized impurity matrix elements

ii_scattering
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. it calculates the the carrierionized impurity scattering rate

ii_only
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. it calculates only the ionizedimpuritylimitted mobility

ii_lscreen
¶
Type 
LOGICAL

Default 
.true.

Description 
If .true. it calculates and uses freecarrier screening of ii_g matrix elements, else calculations will
diverge with increasing density of kpoint due to 1/(q^4) divergence for ionized impurity scattering rate

ii_partion
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. it accounts for partial ionization

ii_charge
¶
Type 
REAL

Default 
1.0

Description 
Charge of the ionized impurities in units of elementary charge

ii_n
¶
Type 
REAL

Default 
0.0d0

Description 
Density of impurities, input in units of cm^3 (cm^2 in 2Dcurrently under development)

ii_eda
¶
Type 
REAL

Default 
0.0d0

Description 
Ionization energy of the donor or accpetor impurity, for partial ionization calculations

kerread
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. read Kp and Km kernels from files .ker when solving the realaxis Eliashberg equations.

kerwrite
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. write Kp and Km kernels to files .ker when solving the realaxis Eliashberg equations.

kmaps
¶
Type 
LOGICAL

Default 
.false.

Description 
Generate the map k+q –> k for folding the rotation matrix U(k+q). If .true., the program reads ‘prefix.kmap’ and ‘prefix.kgmap’ from file. If .false., they are calculated.
Note that for a restart with epwread =.true., kmaps also needs to be set to true (since the information to potentially calculate kgmaps is not generated in a restart run). However, the files “prefix.kmap” and “prefix.kgmap” themselves are actually not used if epwread=.true. and hence need not actually be there.

lacon
¶
Type 
LOGICAL

Default 
.false.

Description 
laniso
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. solve the anisotropic Eliashberg equations on the imaginaryaxis. To solve the equations,
*.ephmat , *.freq , *.egnv , and *.ikmap files should be provided. These files are described under ephwrite variable. 
lifc
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. uses the realspace interatomic force constant generated by q2r.x. The resulting file must be named “ifc.q2r”. The file has to be placed in the same directory as the dvscf files. In the case of SOC, the file must be named “ifc.q2r.xml” and be in xml format. See asr_typ for the type of acoustic sum rules that can be imposed.

limag
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. solve the imaginaryaxis Eliashberg equations.

lindabs
¶
Type 
LOGICAL

Default 
.false.

Description 
liso
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. solve the isotropic Eliashberg equations on the real or imaginaryaxis. To solve the equations provide either: (1) Eliashberg spectral function file using fila2f variable. (2)
*.ephmat , *.freq , *.egnv , and *.ikmap files. These files are described under ephwrite variable. 
lpade
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. Padé approximants to continue the imaginaryaxis Eliashberg equations to realaxis. This works with limag =.true.

lphase
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. then fix the gauge for the interpolated dynamical matrix and electronic Hamiltonian.

lpolar
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. enable the correct Wannier interpolation in the case of polar material.

lreal
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. solve the Eliashberg equations directly on the realaxis. Only the isotropic case (liso =.true.) is implemented.

lscreen
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. the elph matrix elements are screened by the RPA or TF dielectric function. See (scr_typ).

lunif
¶
Type 
LOGICAL

Default 
.true.

Description 
If .true. a uniform frequency grid is defined between (wsfc,wscut) for solving the realaxis Eliashberg equations. Works only with lreal =.true.

longrange
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. only the longrange part of the electronphonon matrix elements are calculated. Works only with lpolar =.true.

loptabs
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. optical absorption spectra including phononassisted and direct transitions using quasidegenerate perturbation theory.

len_mesh
¶
Type 
INTEGER

Default 
1

Description 
Number of quasidegenerate meshgrids for optical absorption spectra using quasidegenerate perturbation theory.

max_memlt
¶
Type 
REAL

Default 
2.85d0

Description 
Maximum memory that can be allocated per pool in [Gb].

meff
¶
Type 
REAL

Default 
12.0

Description 
Density of state effective mass for electronplasmon.

mob_maxiter
¶
Type 
INTEGER

Default 
50

Description 
Maximum number of iteration during the IBTE.

mp_mesh_k
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true., fine electronic mesh is in the irr. wedge, else a uniform grid throughout the BZ is used.

mp_mesh_q
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true., fine phonon mesh is in the irr. wedge, else a uniform grid throughout the BZ is used. Not currently in use.

meshnum
¶
Type 
INTEGER

Default 
1

Description 
Final meshgrid to be performed using quasidegenerate perturbation theory, maximum value:ref:len_mesh  1, used with start_mesh for restart calculations.

ncarrier
¶
Type 
REAL

Default 
1.0d+13

Description 
If carrier = .true. then compute the intrinsic mobility with ncarrier concentration (in cm^3). If ncarrier is positive it will compute the electron mobility and if it is negative it will compute the hole mobility. If int_mob is also .true. then it will compute both the electron and hole mobility, which is the recommended way to compute mobility.

nc
¶
Type 
REAL

Default 
4.0d0

Description 
Number of carriers per unit cell that participate to the conduction in the Ziman’s resistivity formula. Typically this corresponds to the number of bands crossing the Fermi level. This can be a fractional number.

nest_fn
¶
Type 
LOGICAL

Default 
.false.

Description 
Calculate the electronic nesting function.

ngaussw
¶
Type 
INTEGER

Default 
1

Description 
Smearing type for FS average after Wannier interpolation

nk1, nk2, nk3
¶
Type 
INTEGER

Default 
0

Description 
Dimensions of the coarse electronic grid, corresponds to the nscf calculation and wfs in the outdir.

nkf1, nkf2, nqf3
¶
Type 
INTEGER

Default 
0

Description 
Dimensions of the fine electron grid, if filkf is not given.

nq1, nq2, nq3
¶
Type 
INTEGER

Default 
0

Description 
Dimensions of the coarse phonon grid, corresponds to the nqs list.

nqf1, nqf2, nqf3
¶
Type 
INTEGER

Default 
0

Description 
Dimensions of the fine phonon grid, if filqf is not given.

npade
¶
Type 
INTEGER

Default 
90

Description 
Percentage of Matsubara points used in Padé continuation.

nqsmear
¶
Type 
INTEGER

Default 
10

Description 
Number of different smearings used to calculate the a2f.

nsiter
¶
Type 
INTEGER

Default 
40

Description 
Number of iteration for the selfconsistency cycle when solving the real or imaginaryaxis Eliashberg equations.

nsmear
¶
Type 
INTEGER

Default 
1

Description 
Number of different smearings used to calculate the phonon selfenergy.

nstemp
¶
Type 
INTEGER

Default 
1

Description 
Number of temperature points used for superconductivitiy, transport, indabs, etc.. If nstemp is left blank, or is equivalent to the number of entries in temps(:), then the temperatures provided in temps(:) are used. If nstemp>2 and only two temperatures are given in temps(:), then an evenly spaced temperature grid with steps between points given by (temps(2)  temps(1)) / (nstemp1) is generated. This grid contains nstemp points. nstemp cannot be larger than 50.

nswi
¶
Type 
INTEGER

Default 
0

Description 
nswc
¶
Type 
INTEGER

Default 
0

Description 
nswfc
¶
Type 
INTEGER

Default 
0

Description 
nq_init
¶
Type 
INTEGER

Default 
1

Description 
Phonon occupation for quasidegenerate perturbation theory, 1 for BoseEinstein, 2 for integer BoseEinstein, 3 for MonteCarlo method of integration.

muc
¶
Type 
REAL

Default 
0.d0

Description 
Effective Coulomb potential used in the Eliashberg equations.

nw
¶
Type 
INTEGER

Default 
10

Description 
Number of bins for frequency scan in delta( e_k  e_k+q  w).

nw_specfun
¶
Type 
INTEGER

Default 
100

Description 
Number of bins for frequency in electron spectral function.

phonselfen
¶
Type 
LOGICAL

Default 
.false.

Description 
Calculate the phonon selfenergy from the elph interaction.

plselfen
¶
Type 
LOGICAL

Default 
.false.

Description 
prefix
¶
Type 
CHARACTER

Default 
‘pwscf’

Description 
Prepended to input/output filenames. Must be the same used in the calculation of the wfs and phonons.

prtgkk
¶
Type 
LOGICAL

Default 
.false.

Description 
Allows to print the electronphonon vertex g (in meV) for each qpoint, kpoint, iband, jband and modes.
Note: Average over degenerate iband, jband and modes is performed but not on degenerate k or qpoints.
Warning: this produces huge text data in the main output file and considerably slows down the calculation.
Suggestion: Use only 1 kpoint (like Gamma).

pwc
¶
Type 
REAL

Default 
1.0

Description 
QD_bin
¶
Type 
REAL

Default 
0.1

Description 
Size of manybody meshgrid for quasidegenerate perturbation theory (in eV).

QD_min
¶
Type 
REAL

Default 
0.0

Description 
Starting energy for quasidegenerate perturbation theory (in eV).

rand_nq, rand_nk
¶
Type 
INTEGER

Default 
1

Description 
number of random q,kvectors on the fine mesh

rand_q, rand_k
¶
Type 
LOGICAL

Default 
.false.

Description 
q/kvectors on the fine mesh are generated randomly

restart
¶
Type 
LOGICAL

Default 
.false.

Description 
Create a restart point every restart_step qpoints from the fine grid during the interpolation stage.

restart_filq
¶
Type 
CHARACTER

Default 
'' 
Description 
Input file to restart from an exisiting qfile. Use to merge different qgrid scattering rates.

restart_step
¶
Type 
INTEGER

Default 
100

Description 
Frequency of restart points during the fine qgrid interpolation phase. This produces restart files called XXX.sigma_restart1

scr_typ
¶
Type 
INTEGER

Default 
0

Description 
If 0 calculates the Lindhard screening, if 1 the ThomasFermi screening. Only relevant if lscreen = .true.

scatread
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. the current scattering rate file is read from file.

scattering
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. computes scattering rates. See also scattering_serta for the type of scattering.

scattering_serta
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. computes scattering rates in the selfenergy relaxation time approximation. See S. Poncé, E. R. Margine and F. Giustino, Phys. Rev. B 97, 121201 (2018) for more information.

scattering_0rta
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. then the scattering rates are calculated using 0th order relaxation time approximation.

scissor
¶
Type 
REAL

Default 
0.0

Description 
Gives the value of the scissor shift of the gap (in eV).

selecqread
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. then restart from the selecq.fmt file

smear_rpa
¶
Type 
REAL

Default 
0.05d0

Description 
Smearing for the calculation of the Lindhard function (in eV). Only relevant if lscreen = .true.

specfun_el
¶
Type 
LOGICAL

Default 
.false.

Description 
Calculate the electron spectral function from the eph interaction. The relevant variables in this case are wmin_specfun, wmax_specfun and nw_specfun.

specfun_ph
¶
Type 
LOGICAL

Default 
.false.

Description 
Calculate the phonon spectral function from the eph interaction. The relevant variables in this case are wmin_specfun, wmax_specfun and nw_specfun.

specfun_pl
¶
Type 
LOGICAL

Default 
.false.

Description 
Calculate electronplasmon spectral function. The relevant variables in this case are wmin_specfun, wmax_specfun and nw_specfun. See also nel, meff, epsiHEG.

system_2d
¶
Type 
CHARACTER

Default 
‘no’

Description 
‘no’ then 3D bulk materials
‘gaussian’ then the longrange terms include dipoles only and the range separation function is approximated by a Gaussian following Ref. Phys. Rev. B 94, 085415 (2016)
‘dipole_sp’ then the longrange terms include dipoles following PRB 107, 155424 (2023)
‘quadrupole’ then the longrange terms include dipoles and quadrupoles terms following PRL 130, 166301 (2023) and requires the presence of a “quadrupole.fmt” file.
‘dipole_sh’ then the longrange terms include dipoles following [PRB 105, 115414 (2022)]

shortrange
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. then computes the shortrange part of the electronphonon matrix elements. Works only with lpolar =.true.

start_mesh
¶
Type 
INTEGER

Default 
1

Description 
Starting mesh for optical absorption for quasidegenerate perturbation theory, used with meshnum for restart calculations.

temps
¶
Type 
REAL(nstemp)

Default 
300.d0 Kelvin

Description 
Temperature values used in superconductivitiy, transport, indabs, etc. in kelvin unit. If no temps are provided, temps=300 and nstemp =1. If two temps are provided, with temps(1)<temps(2) and nstemp >2, then temps is transformed into an evenly spaced grid with nstemp points, including temps(1) and temps(2) as the minimum and maximum values, respectively [Ex)
nstemp = 5 temps = 300 500 ]. In this case, points are spaced according to (temps(2)  temps(1)) / (nstemp1). Otherwise, temps is treated as a list, with the given temperatures used directly [Ex) temps = 17 20 30 ]. No more than 50 temperatures can be supplied in this way. 
tc_linear
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. linearized Eliashberg eqn. for superconducting transition temperature Tc will be solved.

tc_linear_solver
¶
Type 
CHARACTER

Default 
‘power’

Description 
Algorithm to solve Tc eigenvalue problem. Possible algorithms are ‘power’, and ‘lapack’.

vme
¶
Type 
CHARACTER

Default 
‘wannier’

Description 
if ‘dipole’ then computes the velocity as dipole+commutator = <psi_{mk} p+i[V_{NL},r] psi_{nk}>`. If ‘wannier’ then computes the velocity as dH_nmk/dk  i(e_nke_mk)A_nmk where A is the Berry connection. Note: Before v5.4, vme = .FALSE. was the velocity in the local approximation as <psi_mkppsi_nk>. Before v5.4, vme = .TRUE. was the same as ‘wannier’.

wannierize
¶
Type 
LOGICAL

Default 
.false.

Description 
Calculate the Wannier functions using W90 library calls and write rotation matrix to file ‘filukk’. If .false., filukk is read from disk.

wepexst
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. then prefix.epmatwe files are already on disk (don’t recalculate). This is a debugging parameter.

wmax
¶
Type 
REAL

Default 
0.3d0

Description 
Max frequency in \(\delta( \epsilon_{\bf k}  \epsilon_{\bf{k}+\bf{q}}  \omega)\).

wmax_specfun
¶
Type 
REAL

Default 
0.d0

Description 
The upper boundary for the frequency in the electron spectral function in [eV].

wmin
¶
Type 
REAL

Default 
0.d0

Description 
Min frequency in \(\delta( \epsilon_{\bf k}  \epsilon_{\bf{k}+\bf{q}}  \omega)\).

wmin_specfun
¶
Type 
REAL

Default 
0.d0

Description 
The lower boundary for the frequency in the electron spectral function in [eV].

wscut
¶
Type 
REAL

Default 
1.d0

Description 
Upper limit over frequency integration/summation in the Eliashberg equations in [eV]. For limag =.true., wscut is ignored if the number of frequency points is given using variable nswi.

auto_projections
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. then automatically generate initial projections for Wannier90. It requires scdm_proj =.true.

dis_froz_min, dis_froz_max
¶
Type 
REAL

Default 
1d3, 0.9d3

Description 
Window which includes frozen states for Wannier90. See wannier90 documentation.

dis_win_max
¶
Type 
REAL

Default 
1d3, 1d3

Description 
Maximum value of the outer window. See wannier90 documentation.

iprint
¶
Type 
INTEGER

Default 
2

Description 
Verbosity level of Wannier90 code. See wannier90 documentation.

num_iter
¶
Type 
INTEGER

Default 
200

Description 
Number of iterations passed to Wannier90 for minimization. See wannier90 documentation.

proj(:)
¶
Type 
CHARACTER

Default 
'' 
Description 
Initial projections used in the Wannier90 calculation. Simple solution is
proj(1) = 'random' . See wannier90 documentation. 
reduce_unk
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. then plot Wannier functions on reduced grids.

scdm_entanglement
¶
Type 
CHARACTER

Default 
‘isolated’

Description 
Disentanglement type in the SCDM algorithm.

scdm_mu
¶
Type 
REAL

Default 
0.d0

Description 
Parameter for Wannier functions via SCDM algorithm.

scdm_proj
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. then calculate MLWFs without an initial guess via the SCDM algorithm.

scdm_sigma
¶
Type 
REAL

Default 
1.d0

Description 
Parameter for Wannier functions via SCDM algorithm.

wannier_plot
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. then plot Wannier functions.

wannier_plot_list
¶
Type 
CHARACTER

Default 
'' 
Description 
Field read for parsing Wannier function list.

wannier_plot_radius
¶
Type 
REAL

Default 
3.5d0

Description 
Cutoff radius for plotting Wannier functions.

wannier_plot_scale
¶
Type 
REAL

Default 
1.0d0

Description 
Scaling parameter for cube files.

wannier_plot_supercell
¶
Type 
INTEGER(3)

Default 
(/5,5,5/)

Description 
Size of supercell for plotting Wannier functions

wdata(:)
¶
Type 
CHARACTER

Default 
'' 
Description 
Any extra inforumation to be used in the Wannier90 calculation should be included here. These characters will be written to the ‘prefix.win’ file. For example to plot the first Wannier function in xcrysden format:
—————————————————–
wdata(1) = 'wannier_plot = true' wdata(2) = 'wannier_plot_list : 1' —————————————————–
See wannier90 documentation.

plrn
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. polaron calculations are activated.

type_plrn
¶
Type 
INTEGER

Default 
1

Description 
Polaron type, 1 for electron polaron and 1 for hole polaron.

init_plrn
¶
Type 
INTEGER

Default 
1

Description 
Method to initialize the polaron wavefunction in the selfconsistent loop. 1 for Gaussian wave function initialization (see init_sigma_plrn). 6 for fixed atomic displacement configuration \(\{\Delta \tau_{\kappa\alpha p}\}\) initialization (see init_ntau_plrn).

init_sigma_plrn
¶
Type 
REAL

Default 
4.6

Description 
Width (in bohr) of Gaussian initialization wave function, \(A_{n\mathbf{k}} = \exp(\sigma_p\mathbf{k}\mathbf{k}_0)\), where \(\mathbf{k}_0\) is given by init_k0_plrn.

init_k0_plrn
¶
Type 
REAL, DIMENSION(3)

Default 
\(\mathbf{k}_{\mathrm{CBM/VBM}}\)

Description 
\(\mathbf{k}\)point (in crystal coordinates) in which the initialization Gaussian wave packet is centered.

init_ntau_plrn
¶
Type 
INTEGER

Default 
1

Description 
Number of atomic displacements configurations to be considered if init_plrn =6. If init_ntau_plrn=1, the displacements are read from the dtau_disp.plrn file. If init_ntau_plrn=N>1, the displacements are read from the dtau_disp.plrn_i, where i=1, …, N, files.

conv_thr_plrn
¶
Type 
REAL

Default 
1.0d5

Description 
The converge threshold in the ab initio polaron equations (in bohr). The selfconsistency is achieved when \(\max\Delta \tau^{\mathrm{save}}_{\kappa\alpha p}  \Delta \tau_{\kappa\alpha p} < \varepsilon_\mathrm{scf}\).

niter_plrn
¶
Type 
INTEGER

Default 
50

Description 
The maximum number of iterations in the selfconsistent loop in the ab initio polaron equations.

ethrdg_plrn
¶
Type 
REAL

Default 
1.0d6

Description 
Converge threshold (in Ry) in the diagonalization of the effective polaron Hamiltonian.

adapt_ethrdg_plrn
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. the adaptive diagonalization threshold for the effective polaron Hamiltonian is activated.

init_ethrdg_plrn
¶
Type 
REAL

Default 
1.0d2

Description 
Initial coarse threshold (in Ry) to be considered in the diagonalization of the effective polaron Hamiltonian.

nethrdg_plrn
¶
Type 
INTEGER

Default 
11

Description 
Number of adaptive diagonalization thresholds to be considered, in logarithmic steps, until reaching final ethrdg_plrn.

io_lvl_plrn
¶
Type 
INTEGER

Default 
0

Description 
I/O level of polaron calculations. If io_lvl_plrn=1, write/read electronphonon matrix elements to file. If io_lvl_plrn=0, keep them in memory.

restart_plrn
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. selfconsistent solution of polaron equations is skipped and postprocessing calculations are activated.

interp_Bqu_plrn
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. \(B_{\mathbf{q}\nu}\) is interpolated into the fine qgrid or path.

interp_Ank_plrn
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. \(A_{n\mathbf{k}}\) is interpolated into the fine kgrid or path.

cal_psir_plrn
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. the realspace polaron wavefunction \(\Psi(\mathbf{r})\) is calculated (see step_wf_grid_plrn). Output file is written in .xsf format (psir_plrn.xsf).

step_wf_grid_plrn
¶
Type 
INTEGER

Default 
1

Description 
Write \(\Psi(\mathbf{r})\) only in every step_wf_grid_plrn grid point of the original grid, given by the Wannier function .cube files.

scell_mat_plrn
¶
Type 
LOGICAL

Default 
.false.

Description 
If .true. the nondiagonal supercell calculation is activated for polarons.

scell_mat
¶
Type 
INTEGER, DIMENSION(3, 3)

Default 
(/ (/1, 0, 0/), (/0, 1, 0/), (/0, 0, 1/) /)

Description 
Transformation matrix \(S\) from the unit cell to the (in general nondiagonal) supercell. \(\vec{a}_{s} = S \vec{a}_p\), where \(\vec{a}_{s}\) and \(\vec{a}_{p}\) indicate supercell and the unit cell lattice vectors, respectively.

ZG.x and disca.x input flags are provided in this link.